# Evaluating $\int x^{x^x}\,\mathrm dx$

How do I evaluate $$\int x^{x^x}\,\mathrm dx\ ?$$

I tried using integration by parts but couldn't do it. Please solve it for me. I found it in unsolved questions of maths calculus.

• Could you show us your efforts in solving the problem? – Chandler Watson Sep 5 '15 at 16:26
• what do you exspect? – Dr. Sonnhard Graubner Sep 5 '15 at 16:28
• Given the fact there does not exist a closed form for $\int x^x \mathrm{d}x$, it would amaze me if there is one for this one. – Nigel Overmars Sep 5 '15 at 16:29
• It is an unsolved question because a closed form can't be found. – Siminore Sep 5 '15 at 16:30
• Congratulations, this is now the Rahul function! – mickep Sep 5 '15 at 18:06